Chopping block scraper



Sept. 24, 1935. H. E. HARKIN 'QHOPPING Lo cx SCRAPER Filed Aug. .25 1934 2 Sheets-Sheet 2 m m ml K m. u/ v r 5 IT as H I Patented Se t. 2t, 1935 UNITED STA-T S PATENT OFFICE 2,015,220 cnorrme BLocK soahrnn m E. nuns, momma Park, N. J. Application August-25, "1934, Serial No. 741,383 ,6 Claims. (01. 144-115 This invention relates to a wood-working tool which-can best be described as -a scraper, for cutting the surface and more particularly irregular surfaces of an area of wood such as the top of a chopping block. While it may serve for various other purposes, among the objects .of my invention are the production of a tool that can be easily handled and will economically dress any regular wood surface as the top of a chopping block, or, other like surface where similar diiiiculties of treatment exist.

A butcher's chopping block is now-usually made ,of a large number of heavy pieces of wood with their grain running vertically or irregular, but

driven at high speed with a multiplicity of slight,

presenting" a top surface, when all the pieces are doweled and bolted together, a generally level top. While the use of the block results in greater wear because of more frequent chopping onthe middle portion, irregular cuts due to incidents in use, or due to slight variations in hardness at the protruding end of the difierent sections composing theblock, result in irregularities :.horizontal section 01! the topflwhich involves considerable cost periodically. v My scraper involves special 'cuttingsurfa "cutting edges, but with flexibility to m'ake the cutting tool, effective ona concave or even a slightly irregular surface. It provides in particular thatthe operation of the'tool can effect a cutting with any desired concavity of the top surface, but still finishthe surface with-all desired smoothness. fleeting 'all the requirements. of peculiarshape and conditions and the character of the woofid which is usually a suitable g grade of oak or aple, it provides a simple tool easily handled and economically operated for time-saving and convenient finishing by any one at odd times occupied in the shop; 4

While my invention may be embodled in a varietyof foisns'andmbdiflcations may be made to suit particular conditions, I have in the accompanying drawings illustrated a particular form which has been made and successfully used with allthe advantages hereinbefore mentioned. The form of my invention shownin tlre accomp ming drawings comprises:

I is a. side elevati n; of a chopping block,

partout away,v with a scraping. tool positioned on the concave surface.

Fig. II is a side-perspective view of thetool on a larger scale. I

Flg..III is a vertical section of the tool. Fig. TV is a bottom view of the tool base.

. Fi V is -.a bottom view of the base with the 1 base cover plate removed showing the driving Fig. VI is a side view of one of the driving gears with the flexible -disc; scraper in upside do position. Fi VII is a section on line VII- -VJI of Fig. VI. Th dropping block A may be of any usual form, that illustrated being section or built-up chopping blocks now generally in use, with a series of sections of wood on end clamped to- 'gether bybog's in one direction; doweled at the ends and with suitable legs. With a slightly concave top of the chopping block, the scraping go tool B is adapted to beoperated over the entire.

e upper surface \with a suitable current wire 0 connected with a socket, so as to supplycurrent for the motor in the tool during its desired range of movement;

. The tool B in the form shown, comprises a base I having a removable base-plate 2 and a motor armature 3, with ashaft 4 and fields 5, and a -I top pivot connection 8. I

The entire, motor mechanismis covered'and 0 protected by a casing l, to which an arm or I handle 8 is rigidly attached and the electrical connections C-'C, and a suitable switch 9 for ready manipulation to turn on and oil the current operating the tool.

The motor shaft 4 extends through the base I 4 and drives gear it, 'which meshes with genre I I, H', which i-n'this case have a ratio of about 6'to i, so that with normal speed .of a small motor the cutters-or scraping discs may be turned 40 at a'mosteffective scraping speed.

.may manipulate the tool-by grasping the handle 8 and th knob l2, and direct the tool and exert the'desired' balanced pressure on the cutters in 5 the course of operation. I

Having the two cutting discs symmetrically loca n opposite sldes of the motor shaft the main o'ldweight. of the tool balances the tool and contributes to the ease ofmanipulation.

. The cutting disciqi has a crlmped middlej dii ametrical rib l4, which is cut away near its 1 middle,; with an-incision l5 into which the stud pivot, l6, attached to or formed with base 1, forming a suitably lubricated bearing for, gears The base I has a knob l2, so that an operator' H projects in order to keep the disc centrally located on the "gear. A recess diametrically across each gear accommodates the central rib on the cutting disc, which can therefore be slid 5 from the side of the gear into its fixed contact or support, but with the central rib this support provides for the flexing or springing of each half of the cutting tool when the tool is pressed down upon the wood surface to be cut, dressed or 10 scraped.

The cutting disc or tool is preferably a disc of thin sheet steel suitabl tempered to maintain its initial or normal shipe, which consists of a slight dihedral angle which positions each half 15 away from the horizont l, and in tire position of operative assembly thee two sides or semi-circles of the disc bulge dutwardly beyond the baseplate 2. The base preferably has a series ,of holes I! above the base-plate 2, so that any dust 20 or scrapings that might be picked up by the gears will by centrifugal force be thrown out to the side. In addition, however, the edges .18 of .the holes or apertures in the bottom cover plate 2, are chamfered or beveled so that the dust or 25 scrapings thrown out by rotation of the cutting discswill be driven laterally away from the tool to prevent their ingress to the mechanism.

The base, casing, handle and other parts are preferably made of aluminum, while the cutting 3!! .discs or knives used in the tool would be made of steel or hard. alloys, and after the punching of the holes l9, IS in the discs I prefer to turn over the exuded edge of each perforation so as to providean outwardly directed cutting edge for each 5 of-the perforations, and also to maintain theseries of projections on the disc an equal height above the surface of the disc.

of the holes to form uniform cutting heads or prongs, I may, however, form with special tools 40. in one operation to provide uniformity and suitable cutting edge for the purposes of such a high speed wood-cutting or scraping disc, without any particular sharpening after their formation.

When the perforations have been completed the 45.- entire disc is suitably tempered and hardened,

- and thereupon b and spring-held cutting disc, for the purposes herein described.

It will be noted, particularly fromFigs. VI, VII,

50-- that when the gearwith the'disc is reversed,

compared with the 'other figures, and the gear has been inserted in the casing I, the discs spread sumciently beyond the lower surface of the base I cover 2 so that as the base of the tool is moved over a concave surface the cutting discs will reach into the arc of the depressionof the concavity so as to effectively establish a cutting contact for all of the inequalities it is. desired to remove. .It will thus be seen that in the form of my inventionherein specifically described, a movable hand-controll'ed and manipulated-base has cutting discs and means for revolving the same at high speed, for the purpose of scraping or 65 cutting the irregularsurface over which the tool is moved. The cutting discs have a large numr of sharp rigid projections distributed throughout the surface of eachdisc which pro- :Iect Just enough from but are integral with the 70 fiat surface of the disc in order to effect aslight and predetermined cutting of the surface. As a chopping block isslightly concave, the cutting discs are so constructed as to normally press away from the face of the tool, but they are 75" yielding or spring-pressed in order that they ex- This fashioninges' a suitable cutting tool" ert the maximum cutting effect on the projecting irregularities of the surface, and thereby rapidly accomplish the desired result of produc ing on the entire surface to the desired smooth condition. The spring-pressed cutters project sufficiently so that between the two ends of the base they will effectively reach and scrape or dress uniformly all parts of a generally concave surface by extending sufficiently below the level or planeof the bottom of the base, and having 10 the cutters symmetrically disposed with respect to'the periphery of the bottom of the base, and more particularly equi-distant from the major dimension of the base' of contact with the block.

As the cutters are'easily made of, spring sheet steel the perforations and projecting edges of the metal at each perforation form steel-hard cuttingor scraping points or small cutters. By revolving the cutters at high speeds the cutting or scraping is effected and produces a uniform finished surface suitable for the purpose intended.

By the formation and arrangement of the cutters they can be readily renewed by pulling out the gear from its pivotal mounting, sliding the cutter rib diagonally of the gear, and on replacement of a new one, the return of the gear to its working position causes the pivoted stud to engage the middle of the rib of the cutter,

I and thereby holdit in central registrationwith the gear and with the aperture in the base of the tool. V P

By the chamfering or beveling of the periphery of the opening in the base of the tool the sawdust or wood particles cut away are immediately thrown out laterally in view of the high speed of the cutter, and prevent clogging up of I the gears or cutter. This makes the cutters and the tool self-clearing and insures uniformity of operation and durability.

While a suitable motor is shown mounted on 46:

the tool, the weight in view of the small size of the motor is practical for all operations, and also lends sufficient weight to the tool to maintain a proper degree of uniform pressure to which the' hand pressure may be added to cause suitable v flexing of the cutting discs. The motor connections through suitable lead wires adapt the tool for operation by plugging in the wire at any convenient nearby'socket, thus permitting all the range of operation necessary for the use of the tool.

.While I have shown one article with two cutting discs', and a particular arrangement for motor and gears and replaceable cutters, and this construction has proven fully effective, convenient and economical, many variations may be made without departing from the spirit of my invention. While a specific useful purpose has been cited as the primary object of my design and construction, many other uses, may be found for the tool in its. various forms, and without confining myself to the particular article herein illustrated in the accompanying drawings and describedywhat I claim and desire to secure by Letters Patente'is: 1. A dressing or scraping tool of the class described, having a cutting disc/with integral sharp cutting prongs uniformly projecting. from oneside thereof, adiametrical ridge on the back side of the disc, a rotating'member for attachment to said disc containing means cooperating with i the ridge on the disc so constructed and ar- Eanged that upon assembly for operationjhe utting disc is locked inoperative position, and iii! of the disc on and driving from a rotating memafter operation permitting ready removal for replacement or repair.

2. A dressing or scraping tool for wood surfaces having a base carrying a motor and driving means to a rotating member adjacent the operating working face of the base, a cutter disc adapted to be removably attached to said rotating member, a diametrical fold in said disc so formed and arranged thattwo sides of the disc are normally spring-held at a slight angle onset to the plane of the disc, whereby the two sides of the disc project beyond the plane of the base normally but permit spring recession during operation to meet the conditions of-irregular cut-' ting of the surface being dressed.

3. A cutting disc for wood surface dressing or scraping tool, consisting of a disc having .integral cutting prongs or heads uniformly projecting from a flat surface of one side of 'the disc, at diametrical fold in the disc so. formed and constructed as to provide an initial slight di- 7 hedral angle between the two halves of the disc, and said fold constituting a spring support between said two halves whereby pressure on the. tool will vary the relation of the two halves of 7 the two halvesof the disc for varying angular relation upon operating pressure, and simultane ously constituting a means of operating support her of a scraping tool.

5. A tool adapted for dressing or scraping a concavely irregular wood surface, comprising a mobile base with handles for balanced manipulation, a motor and other driving mechanism comprising the principal dead weight disposed intermediate the handles, a recess on the underside of the base, a plurality of gears in said recess and connections therefrom to the superposed motor, a detachable face plate adapted to hold said gears in position in the recess, a hole in said plate opposite each gear and'a rotating scraping disc with integral cutting prongs having inherent flexibility mounted in said recess and attached to the adjacent gear.

6. A tool for dressing an irregular wood surface with concavities, comprising a manually -operable base fixedly supporting a' motor and cutter driving mechanism, having a rotarily 20 driven mber supported in fixed position with respect z the working contact face? of the base halves each set normally at a slight angle to the plane-of rotation, spring means associated with HARRY E. mm. 

